
Because the
definition of Massey products is different from the definition in
[1]}, the expression of differentials in Corollary REF 
differs from the one in [1]}.

The two specific elements of \(\langle \underbrace{H_3,\cdots ,H_3}\limits _{t+1},x_p\rangle \)  in
Theorem REF  and Corollary REF  are completely
different, and equal \([c(A_1)]\)  and \([c(A_2)]\)  respectively, where
\(c(A_i)\)  \((i=1,2)\)  are related cocycles of the defining systems
\(A_i\)  \((i=1,2)\)  obtained from Theorem REF . The matrices
associated to the two defining systems are given by
\( \left(\begin{array}{ccccccc}H_3 & -H_5 & H_7 & \cdots & (-1)^{t-1}H_{2t+1} & (-1)^tH_{2t+3} & \\& H_3 & -H_5 & \cdots & (-1)^{t-2}H_{2t-1} & (-1)^{t-1}H_{2t+1} & (-1)^tx_{p+2t}^{(t)} \\& & H_3 & \cdots & (-1)^{t-3}H_{2t-3} & (-1)^{t-2}H_{2t-1} & (-1)^{t-1}x_{p+2t-2}^{(t)} \\& & & \ddots & \vdots & \vdots & \vdots \\& & & & H_3 & -H_5 & (-1)^2x_{p+4}^{(t)} \\& & & & & H_3 & (-1)x_{p+2}^{(t)} \\& & & & & & x_p \\\end{array}\right)_{(t+2)\times (t+2)}\) 
and
\(\left(\begin{array}{ccccccc}H_3 & 0 & 0 & \cdots & 0 & 0 & \\& H_3 & 0 & \cdots & 0 & 0 & (-1)^t{x}_{p+2t}^{(t)} \\& & H_3 & \cdots & 0 & 0 & (-1)^{t-1}{x}_{p+2t-2}^{(t)} \\& & & \ddots & \vdots & \vdots & \vdots \\& & & & H_3 & 0 & (-1)^2{x}_{p+4}^{(t)} \\& & & & & H_3 & (-1){x}_{p+2}^{(t)} \\& & & & & & x_p \\\end{array}\right)_{(t+2)\times (t+2),}\) 
respectively. Here \(x_{p+2i}^{(t)}\)  \((1\le i\le t)\)  in the first
matrix are different from those in the second one.


